Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

A Novel DLLME Method Involving a Solidifying Hydrophobic Deep Eutectic Solvent Using Hydrophilic Deep Eutectic Solvent as the Dispersant for the Determination of Polychlorinated Biphenyls in Water Samples

This paper presents a novel dispersive liquid-liquid microextraction (DLLME) method that employs solidified hydrophobic deep eutectic solvent (DES) with hydrophilic DES acting as the dispersant. The aim is to enrich polychlorinated biphenyls (PCBs) from water samples for subsequent determination by gas chromatography-mass spectrometry. The effects of both the hydrophobic DES as the extractant and the hydrophilic DES as the dispersant were thoroughly investigated. Optimization of the key factors influencing extraction efficiency was performed, and the method was subsequently validated. Specifically, a hydrophobic DES called DES2, prepared by combining thymol and decanoic acid in a molar ratio of 3:2, was selected as the extraction solvent. Meanwhile, a hydrophilic DES named DES6, prepared from choline chloride and acetic acid in a molar ratio of 1:2, was chosen as a dispersant. Under the optimal extraction conditions, the developed method exhibited excellent linearity over the concentration range of 0.01-5.0 µg/L, low limits of detection ranging from 3.0 to 5.1 ng/L, relative standard deviations less than 4.1%, and enrichment factors between 182 and 204 for PCBs. Finally, the effectiveness of the developed method was successfully demonstrated through residue determination of PCBs in water samples.

Health benefits and health risks of contaminated fish consumption: Current research outputs, research approaches, and perspectives

Background

Fish contains high-quality omega-3 fatty acids, protein, vitamins, and minerals and due to this it is termed as an essential component of a balanced diet. But there have been concerns raised about the risks of consuming fish that is contaminated with toxins such as methylmercury, polychlorinated biphenyls (PCBs), dioxins, pesticides, and plastic waste. Consumption of contaminated fish containing these pollutants is raising global mortality and morbidity rates.

Scope and approaches

The review examines the current research outputs on the health benefits and potential health risks of fish consumption. The review also discusses various approaches to mitigating the health problems caused by fish consumption, highlights the roles of balancing the risks and benefits when consuming fish.

Key findings and conclusion

Different findings indicated that contaminants cause cancer, kidney failure, adverse neurological effect, cardiovascular diseases, and so on to vulnerable groups such as pregnant, child breast-feeding and children. In conclusion, there is a need to get more tangible evidence about the advantages and disadvantages of fish consumption to safeguard the wellbeing of the society.

Polychlorinated biphenyl congeners in water canals and their relationships with water quality parameters: Insights into their risk assessment

Water pollution with pesticides is one of the most important environmental problems. Polychlorinated biphenyls (PCBs) reach water bodies via agricultural discharge. The aim of this study was to determine the contamination of different water bodies with PCB congeners, and detect the correlation between water quality parameters and seasonal distribution of these PCBs. The results indicated that water canals of AlGharbiah showed the highest ranges of temperature, total dissolved solids (TDS) in spring, and dissolved oxygen (DO) in autumn, while AlQaliobiah water bodies witnessed the highest pH and electrical conductivity (EC) ranges in summer. The highest range of a PCB congener was that of PCB44 (7.96-118.29 µg/g) in sediment samples of Giza, followed by its range (18.01-85.44 µgL-1) in surface water of AlQaliobiah. We found a potential cancer risk from dermal contact with all the investigated PCBs. Principal component analysis (PCA) showed positive correlations between most PCBs and each of EC and TDS, and a negative correlation with DO. While the correlation between PCBs and each of temperature and pH varied according to the geographic location of the governorate. In conclusion, the investigated water canals were contaminated with PCBs, which posed a potential cancer risk and deteriorated water quality.

Phenolic compounds occurrence and human health risk assessment in potable and treated waters in Western Cape, South Africa

Phenolic pollutants from industrial and agricultural activities pose a major threat to the world's potable water supply. The persistent micro-pollutants often find their way into drinking water sources with possible adverse human health implications. In this study, bottled water, tap water, and wastewater treatment plant (WWTP) effluent samples from the Boland region of the Western Cape, South Africa were assessed to determine 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) levels using HPLC/DAD instrumentation. The selected area is known for its vast agricultural ventures and wineries. Evaluation of the human health risk (cancer risk) for the pollutants was conducted using the hazard quotient (HQ). The Ames mutagenicity test was also conducted using the Salmonella typhimurium T98 and T100 strains and the S9 activation enzyme. Trace levels of the phenolics were detected in the samples with a range of 9.32 × 10-7-1.15 × 10-4 mg/L obtained for 4-CP, and 8.80 × 10-7-1.72 × 10-4 mg/L recorded for 2,4-DCP. Both compounds had levels below the limit of 0.01 mg/L prescribed by South African legislation. The assessed HQ for the phenolic concentrations indicates a low level of potential ecological risk and none of the samples had a cancer risk value that exceeded the regulatory limit. The possibility of the analyzed samples causing cancer is unlikely, but non-carcinogenic adverse effects were found. Strong mutagenicity was observed for the T98 strains with a potential ability to cause mutation toward the insertion or deletion of a nucleotide. The T100 bacterial strain showed very slight mutagenicity potential, however, it is unlikely to cause any mutation. The levels of phenolics in the potable water samples may pose a significant threat to human health. Hence, screening persistent organic chemicals in potable water sources and evaluating their potential human health effects is pertinent to prevent associated health challenges.

Exposure to pesticide components causes recurrent pregnancy loss by increasing placental oxidative stress and apoptosis: a case-control study

We investigated the plasma levels of pesticides components namely polychlorinated biphenyls (PCBs), dieldrin, dichlorodiphenyldichloroethylene (DDE), ethion, malathion, and chlorpyrifos in recurrent pregnancy loss (RPL) cases, and tested their associations with placental oxidative stress (OS) biomarkers [nitric oxide (NO.), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), and superoxide dismutase (SOD)] and with placental apoptotic/antiapoptotic indices (Bcl-2 and caspase-3), and evaluated their possible cut-off points to distinguish RPL cases. The study recruited 101 pregnant women divided into; G1 [n = 49, control, normal 1st-trimester pregnancy, normal obstetric history with at least one previous normal live birth], G2 [n = 26, cases with missed abortion (< 3 abortions) before 24 weeks of gestation], and G3 [n = 26, cases with missed abortion (≥ 3 abortions) before 24 weeks of gestation]. The plasma pesticide levels were analyzed by gas chromatography-mass spectrometry. Plasma human chorionic gonadotrophin (HCG), placental OS, Bcl-2, and caspase-3, were analyzed by their corresponding methods and kits. Plasma PCBs, DDE, dieldrin, and ethion levels were significantly higher in RPL cases than in normal pregnancies (p ≤ 0.001). These levels correlated positively with placental OS and apoptosis and negatively with plasma HCG levels. Also, these levels were reliable markers of risk to RPL. Malathion and chlorpyrifos were not detected in any of the study's participants. Pesticides may be risk factors in cases of spontaneous RPL cases. They are associated with an increasing placental OS and placental apoptosis. Specific measures should be taken to decrease maternal exposure to these pollutants' sources, especially in underdeveloped and developing countries.

Toxic Effects of Polychlorinated Biphenyl Congeners and Aroclors on Embryonic Growth and Development

Polychlorinated biphenyls (PCBs) cause significant health and reproductive problems in many vertebrates. Exposure during embryogenesis likely leads to defects in organ development, compromising survival and growth through adulthood. The present study identifies the impact of PCBs on the embryonic development of key organs and resulting consequences on survival and growth. Zebrafish embryos were treated with individual PCB congeners (126 or 104) or one of 4 Aroclor mixtures (1016, 1242, 1254, or 1260) and analyzed for changes in gross embryonic morphology. Specific organs were assessed for defects during embryonic development, using a variety of transgenic zebrafish to improve organ visualization. Resulting larvae were grown to adulthood while survival and growth were assayed. Embryonic gross development on PCB treatment was abnormal, with defects presenting in a concentration-dependent manner in the liver, pancreas, heart, and blood vessel organization. Polychlorinated biphenyl 126 treatment resulted in the most consistently severe and fatal phenotypes, whereas treatments with PCB 104 and Aroclors resulted in a range of more subtle organ defects. Survival of fish was highly variable although the growth rates of surviving fish were relatively normal, suggesting that maturing PCB-treated fish that survive develop compensatory strategies needed to reach adulthood. Life span analyses of fish from embryogenesis through adulthood, as in the present study, are scarce but important for the field because they help identify foci for further studies. Environ Toxicol Chem 2021;40:187-201. © 2020 SETAC.

Spatial and temporal trends of polychlorinated biphenyls in water and sediment from Nairobi River, Kenya

Polychlorinated biphenyls (PCBs) are chemicals that have become ubiquitous environmental pollutants due to their past use, persistence, and long-range transport thus requiring continuous monitoring. Therefore, this research was carried out to investigate spatial and temporal trends of seven indicator PCBs and two others (PCB 105 and PCB 156) in the Nairobi River. Levels of PCBs ranged from below detection limit (bdl) to 157.64 ± 1.52 ng g^-1 and bdl to 718.78 ± 1.71 ng L^-1 for sediment and water, respectively. PCBs 28, 138, and 153 were the most dominant contributing 33.4%, 17.9%, and 14.5% to the total PCBs in sediments and 54.6%, 19.3%, and 14.1% to the total PCBs in water. There was a general increase in ΣPCBs from 18.89 to 151.18 ng g^-1 for sediments and 275.52 to 429.84 ng L^-1 for water as the River flowed downstream. The dry season recorded the highest ΣPCB in sediments while the rainy season recorded the highest ΣPCBs in water, with levels exceeding the WHO water quality guidelines. Risk assessment revealed that populations living downstream are exposed to high levels of PCBs through the consumption of water. Levels of ΣPCBs downstream also exceeded the sediment quality guidelines meaning that aquatic organisms are threatened.

Distribution pattern of persistent organic pollutants in aquatic ecosystem at the Rosetta Nile branch estuary into the Mediterranean Sea, North of Delta, Egypt

The objective of this study was to evaluate the distribution pattern of persistent organic pollutants in water, sediment and aquatic biota represented by Oreochromis niloticus and Donax trunculus at the Rosetta Nile branch estuary. α-HCH, p,p'-DDE and polychlorinated biphenyls were the predominant compounds detected at ranges of 0.54-4.90 ng/l water, 0.75-2.41 ng/g, d. wt. sediment and 2.19-28.11 ng/g, fresh wt. biota. β and γ-HCHs, endosulfan compounds, heptachlor and heptachlor epoxide were at low detection frequencies. Totally, the organochlorine pollutants were at high levels and abundances in Donax spp. than in Tilapia spp. followed by sediment and water. These levels were ranged between lower and higher than those found by the other studies established in Egypt, and well below its tolerable residue levels in fish. A correlation was found for the quantified pollutants between water, sediment and biota. This is clearly reflecting the bioaccumulation properties of these compounds.

Occurrences of Organochlorine Pesticides along the Course of the Buffalo River in the Eastern Cape of South Africa and Its Health Implications

Most organochlorine pesticides (OCPs) which are increasingly used in agriculture and industry are not biodegradable and thereby persist in the environment for a very long period of time. They are capable of negatively impacting the health of humans and biota when present in a higher concentration than recommended. This study evaluated the concentrations of 17 OCPs in surface water samples collected from six sampling sites along the course of the Buffalo River in Eastern Cape, South Africa, between December 2015 and May 2016. The samples were subjected to solvent extraction, followed by florisil clean up, and analyzed using gas chromatography coupled with an electron capture detector. The individual concentrations of OCPs detected ranged from <LOD to 4403 ng/L in summer and <LOD to 313 ng/L in autumn. The levels of OCPs in the study area were generally above the United State Environmental Protection Agency (USEPA) limit of 100 ng/L in all the sampling locations in the two seasons. The cancer risk assessment values were below the permissible limit of the 10⁻⁶ level, although the life average daily dose were slightly above the USEPA maximum limits of 10⁻⁴. Therefore, there is a need for the adequate regulation of agrochemical storage, use, and disposal in this province and other parts of South Africa.

Assessment of the Pollution Status of Eleyele Lake, Ibadan, Oyo State, Nigeria

BACKGROUND

Lakes are a vital water resource, but are adversely affected by pollutants such as heavy metals and polychlorinated biphenyls (PCBs) from urban, agricultural and industrial activities. This can give rise to potential pollution-related health problems such as cancer and infectious diseases. Risk assessments are necessary to determine the degree of pollution and its effects on human health and ecological systems.

OBJECTIVES

This study assessed the pollution status and a risk assessment was calculated to determine the degree of the pollution and its effects on the human health and the ecological system of Eleyele Lake in Ibadan, Nigeria.

METHODS

Physical and chemical parameters, heavy metals and PCBs were determined in the lake water using standard methods from December 2013 to February 2014 at ten different sites of anthropogenic activity.

RESULTS

Water pH ranged from 6.00-7.50, while electrical conductivity ranged from 205.00-221.00 μs/cm³. Dissolved oxygen ranged from 0.30-6.00 mg/L and total dissolved solids ranged from 105.00-113.00 mg/L. Phosphate levels ranged from 13-0.99 mg/L. Nitrate and sulphate in the dry season ranged from (3.10-3.80 and 35.81-40.97 mg/L) and (0.12-0.37 and 6.10-10.30 mg/L) in the wet season. Heavy metal concentrations were in the order cadmium (Cd) > zinc (Zn) > copper (Cu) > chromium (Cr) > lead (Pb) for the dry season and Cd > Zn > Cr > Pb > Cu for the wet season. Total PCBs ranged from 493.90-732.55 μg/L and 52.00-390.03 μg/L for the dry and wet seasons, respectively. All determined physical and chemical parameters were within permissible levels, while heavy metals and PCB concentrations were higher than permissible levels.

DISCUSSION

The hazard quotients and carcinogenic risk values were greater than acceptable limits, indicating that PCBs in Eleyele lake water pose adverse health effects to the local population. It was observed in this study that lower chlorinated PCBs were more prevalent than higher chlorinated PCBs. This may be attributed to the fact that the lower chlorinated PCBs are influenced by atmospheric deposition as a result of their volatility, and they are more susceptible to atmospheric transport than highly chlorinated PCBs.

CONCLUSIONS

PCBs possess serious health risks to the population that depends on the lake as a source of domestic water and its aquatic organisms. Efforts are needed to reduce anthropogenic influence on the lake through strict environmental controls.